SIS 661FM2-Realtek 8201BL LAN (PHY):slowest downloads in house!

I get from 250 to 300kB/s on 3 other PC's here, most about 295 constantly, but this one "clone" unit gets from 80 to 200, mainly 180 or so consistently. I have searched a few times over the years, and wanted to find out if there is any additional info on tuning or tweaking this onboard network adapter.

There have been no recent and specific BIOS, Networking or Kernel settings posted lately, and in addition, have not found confirmation if just getting a $25 PCI (2.2) network card would make a difference.

Yes I know this is (relatively) old tech, but it's been a workhorse here, and I just wanted to see if there is anything I can do for the downloading speed deficiency. It's the #1 PC as listed in my sig.